Prognostic impact of the metastatic lymph node number in intrahepatic cholangiocarcinoma

Development and external validation of a prognosis model to predict outcomes after curative resection of early-stage intrahepatic cholangiocarcinoma

Background

Early-stage intrahepatic cholangiocarcinoma (ESICC) with curative resection and lymph node-negative still has the risk of poor prognosis, and there lacks prognosis-assessing tools for these patients. The objective of this study was to develop a prognosis model to predict outcomes and identify risk stratification for ESICC after resection.

Methods

Totally 263 patients with ESICC after hepatectomy from January 2012 to January 2022 were analyzed. Clinicopathological factors were selected using multivariable Cox regression analysis and a prognosis model was developed. The performance of the model was evaluated by concordance index (C-index), calibration plots, decision curves analysis (DCA), and net reclassification index (NRI). Kaplan-Meier curves were analyzed for risk stratification of overall survival (OS) and recurrence-free survival (RFS) based on the prognosis model.

Results

The clinicopathological features that were independently associated with OS of ESICC included carbohydrate antigen19-9, carcinoembryonic antigen, tumor size, tumor differentiation, and T stage. The prognosis model based on these prognostic factors demonstrated excellent discriminatory performance in both derivation cohort (C-index, 0.71) and external validation cohort (C-index, 0.78), which outperformed the TNM staging system (C-index, 0.59) and individual prognostic factors (all C-index < 0.7). Calibration plots, DCA and NRI also showed superior predictive performance. According to the risk for survival, the model stratified patients into low risk (median OS, 66.6 months; median RFS, 24.3 months) and high risk (median OS, 24.0 months; median RFS, 6.4 months) (P < 0.001).

Conclusions

Our prognosis model can robustly predict the outcomes of ESICC after curative resection and provide precise evaluation on prognosis risk, facilitating clinicians to develop individualized postoperative treatment options.

Dynamic evaluation of postoperative survival in intrahepatic cholangiocarcinoma patients who did not undergo lymphadenectomy: a multicenter study

BACKGROUND

The prognosis of Intrahepatic cholangiocarcinoma (ICC) patients who did not undergo lymphadenectomy is difficult to assess. This study aims to have a dynamic evaluation on the postoperative survival of ICC patients by calculating conditional survival.

METHODS

Relevant data were from patients treated in 12 large-scale hospitals from December 2011 to December 2017. The influence of relevant clinical baseline data on the prognosis of ICC patients was analyzed by Cox regression. Conditional survival (CS) is a method that may predict the prognostic probability dynamically. For a patient with x years of survival, the 1-year CS (CS1) may be calculated as CS1= OS(x + 1)/OS(x).

RESULT

A total of 361 patients who met the criteria were included in the study. Conditional survival (CS) means that the patients' prognosis varies with survival time, meanwhile, relevant factors affecting the prognosis have a time-varying effect. The probability of survival assessed by CS1 increased year by year and the 1,2,3-year survival improved from 68.4% to 87.8%, while the postoperative actuarial OS decreased from 69.4% at 1 years to 36.9% at 3 years.

CONCLUSIONS

In terms of CS, the estimated survival for ICC varies with the increase of survival time after excision. Patients who live longer were likely to live longer. At the same time, with the passage of time, the role of the original adverse factors of the tumor would gradually decrease. Conditional survival allows a more accurate assessment of ICC patients who did not undergo lymphadenectomy.

Adequate lymph node dissection is essential for accurate nodal staging in intrahepatic cholangiocarcinoma: A population-based study

PURPOSE

To comprehensively investigate the implications of lymph node dissection (LND) and the prognostic impact of the number of lymph node (LN) metastases on survival in intrahepatic cholangiocarcinoma (ICC) using a large-scale study.

METHODS

Patients who underwent surgical resection for ICC between 2004 and 2018 were identified from the Surveillance, Epidemiology, and End Results (SEER) registries. The Kaplan-Meier and log-rank tests were used to compare cancer-specific survival (CSS) and overall survival (OS) between different groups. Propensity score matching (PSM) and subgroup analyses were performed to balance potential confounding factors. A multivariate Cox proportional hazards regression model was used to identify prognostic factors of survival outcomes. Restricted cubic splines fitted in the Cox proportional hazard regression models were also conducted to examine associations between continuous variables and outcomes.

RESULTS

In all, 1028 patients were enrolled. There were 652 (63.4%) patients undergoing LND, with lymph node metastasis (LNM) confirmed in 212 (32.5%) cases. Patients receiving LND did not show better survival outcomes than those receiving non-LND (NLND). We divided the LND group into two subgroups: patients with LNM (+) and those without LNM (-). Among these three groups, patients with LNM experienced the worst CSS and OS, while NLND patients had similar survival times to LNM (-) patients. Restricted cubic spline analysis indicated that an increased number of LNM was associated with a decreased chance of survival (p < 0.001). Patients who received LND were further categorized as having no nodal metastasis (N0), 1-2 LNM (N1), or ≥3 LNM (N2) according to the number of LNM. The Kaplan-Meier curves showed that the mortality risk of patients with N0, N1, and N2 disease (median CSS, N0 50.0 vs. N1 22.0 vs. N2 14.0 months; median OS, N0 46.0 vs. N1 21.0 vs. N2 14.0 months, all p < 0.01) increased significantly, except for patients who had <6 LNs harvested. On multivariable survival analysis, a higher nodal stage (N1 vs. N0: CSS, hazard ratio [HR] 2.135, 95% CI 1.636-2.788, p < 0.001; OS, HR 2.100, 95% CI 1.624-2.717, p < 0.001; N2 vs. N0: CSS, HR 4.027, 95% CI 2.791-5.811, p < 0.001; OS, HR 3.678, 95% CI 2.561-5.282, p < 0.001) was an independent prognostic risk factor for survival.

CONCLUSIONS

Despite the lack of a clear survival benefit of LND in patients with ICC, a significant positive association between the number of LNM and poor outcomes was observed. We still suggest adequate LND by examining at least six LNs to ensure precise staging. On this basis, the recently proposed nodal classification of N0, N1, and N2 stages may also allow better prognostic stratification of ICC patients.